Sonication Assisted Liquid Extraction SAE

Commercially available high-intensity ultrasonic probes (10 to 500Wcm ) are the most effective sources for laboratory scale sonochemistry. A typical system operates at 24 kHz with an adjustable total power output of up to 200W and also adjustable irradiation times per pulse of a few tenths of a second. Lower intensities can often be used in liquid-solid heterogeneous systems of interest here because of the reduced liquid tensile strength at the liquid-solid interface, and a common ultrasonic cleaning bath (about lWcm ) can often be adequate for SAE. 

In summary, SAE is a rather special case of off-line liquid extraction at higher temperatures, possibly assisted in some cases by the erosion effect on larger solid particles. Increased extraction speed and efficiency of conventional solvent extraction procedures are the main advantages. However, chemical decomposition or other reactions of the analytes is always a possibility to be borne in mind. The chemical consequences of ultrasonic irradiation of organic liquids have been studied much less that those for water, but it has been established that when cavitation occurs almost all organic liquids will generate free radicals. 

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